Hi Selina P.
Use the data given to calculate a, where is is the distance between the vertex and focus to give a, then plug than that into the vertex form of a parabola
Given
vertex (h, k) = (2, -3)
focus (2, -2)
x = 2 is the vertical axis of symmetry
Use the distance formula to find the distance between the vertex and focus
d = SQRT((x2 - x1)2 + (y2 - y1)2)
a = ±1
f(x) = (x - 2)2 - 3
f(x) = x2 - 4x + 1
These two confirm the vertex and focus
You can graph both equations on a graphing calculator or at Desmos .con to confirm the vertex and focus.